I know that without a DPF, my 320d (163ps) will smoke under hard acceleration from time to time. Before I fitted my Spider, I used to see smoke occasionally (always more noticable at night of course) and after fitting, initially it didn't seem to be any worse.

Recently though, It seems to have got worse (only under hard acceleration). I know this is not an exact science but the other night it seemed to be really billowing smoke - I almost felt bad for the people behind!!

I'm not too bothered about the actual smoke itself and performance/running of the engine doesn't seem to have been affected - but does it actually damage the engine in the long run? I've done a search and there is lots of info about over-smoking just being a symptom of over fueling but I couldn't find anything to say whether or not it is actually causing any damage?

how many miles and what year? Has the crank case breather/oil separator been changed? New vortex ones don't need changing very often, but the older 'loo roll' type can clog up quite badly and cause smoke. Also if left for too long they can build up pressure and bang goes the turbo. BMW never used to change them, but recently they change the old type at every inspection 2 and the new type every 3rd oil change. Could also be over - fuellling, but it would have been doing this since you fitted the box.

how many miles and what year? Has the crank case breather/oil separator been changed? New vortex ones don't need changing very often, but the older 'loo roll' type can clog up quite badly and cause smoke. Also if left for too long they can build up pressure and bang goes the turbo. BMW never used to change them, but recently they change the old type at every inspection 2 and the new type every 3rd oil change. Could also be over - fuellling, but it would have been doing this since you fitted the box.

Steve

Thanks for your replies chaps.

Steve - to answer your questions, it's a Sept 06 model with 53K on the clock. Bought it from a dealer with 49K and it had a service before pickup (next one due in 12K according to OBC). Not sure if they would have replaced that part or not tbh. I also notice a slight rattle when between gear changes on hard acceleration when it's cold - but could be just paranoia!

It does always look worse at night with headlights shinning from the rear...like was mentioned, the 2.0 d's do smoke a bit more under load, and with a tune-it box on board, i would expect more smoke anyway...unless it's like the bat mobile i wouldn't worry to much, keep your eye on you oil level and make sure its changed regulary

It does always look worse at night with headlights shinning from the rear...like was mentioned, the 2.0 d's do smoke a bit more under load, and with a tune-it box on board, i would expect more smoke anyway...unless it's like the bat mobile i wouldn't worry to much, keep your eye on you oil level and make sure its changed regulary